Trial Design Research On Super Long Span Reactive Powder Concrete(RPC) Arch Bridge

The main problem that constrains the development of concrete arch bridge to a greater span is the larger self-weight. The construction technology and cost increase dramatically. It will affect the economic efficiency during construction. High-strength and ultra-high strength concrete are one of an effective way to alleviate the self-weight, Reactive Powder Concrete (RPC) is the most potential one. This paper carried out the research on the trial design of super long span RPC arch bridge. The feasibility on the application of RPC in super long arch bridge was analyzed from the mechanical behavior, construction performance and economic performance. The major researches and conclusions in this paper are listed as follows:(1)Taking the Japan’s 600m concrete Arch Bridge as prototype, trial designs on high strength concrete (HSC) and reactive powder concrete (RPC) arch bridge with a main span of 600m are respectively carried out. A 3D-finite element model based on MIDAS/Civil 2010 is established for the arch bridge. According to the Code for Design of Highway Masonry Bridges and Culverts (JTG D61-2005), the strength and stability of RPC arch bridge were calculated. The results show that the strength and stability of RPC arch bridge meet requirements.(2)The trial design of RPC arch bridge was compared with the HSC arch bridge from engineering quantity, the section stiffness of the ring, internal force and stability. The results show that the section of RPC arch bridge can be thin by using the ultra-high performance and ultra-high strength of RPC. Compared with the HSC arch bridge, the ring section thickness of RPC arch bridge is reduced by forty-seven percent. Self-weight and axial force is reduced by forty percent. The project quantity of substructure can be greatly reduced. The longitudinal and lateral stability have been certainly strengthened, because internal force of RPC arch bridge was reduced and the elasticity modulus of RPC was larger than that of HSC.(3) The method of two phase arching was used in construction. Because RPC is lightweight and high-strength, it can reduce numbers of sections, joints, lifting and cable, accelerate the construction progress. Compared with other methods, it has definite advantage in construction.(4)On the basis of trial design, the stress, the cable force and stability in construction stage were analyzed. The results show that zero displacement method that adopted to calculate the cable force can keep the arch rib axis with design axis. It is also beneficial to control the geometric linear in construction. The compressive stress and tensile stress of arch ring in construction stage are below the allowable value of RPC material. The stability safety factor in each construction stage can meet the stipulations of the code by setting on the wind-cable.(5)This paper referenced the research results about the whole life cycle cost of bridge at home and abroad. The whole life cycle cost of RPC bridge and HSC bridge were analyzed. The cost of strengthened structures and user were analyzed emphatically. The results show that the cost of RPC arch bridge in construction is about 0.60 times than that of HSC arch bridge. But the reinforcement cost and customer cost of RPC arch bridge in operating are very little. The whole life cycle cost of RPC arch bridge is below 0.60 times than that of HSC arch bridge. The whole life cycle cost of RPC arch bridge is less than HSC arch bridge.As the above results of research show that the super long span reactive powder concrete(RPC) arch bridge is feasible from mechanical behavior, construction performance and economic performance.